#include <stdio.h>

int main()
{
	int money = 0;
	int total = 0;
	scanf("%d", &money);
	for ( int i = 0; i <= money / 50; i++ )
	{
		total += (money - i * 50) / 20 + 1;
	}
	printf("%d", total);
	return 0;
}
